scholarly journals Nanoelectronic Device Structures at Terahertz Frequency

10.14311/578 ◽  
2004 ◽  
Vol 44 (3) ◽  
Author(s):  
M. Horák
Keyword(s):  
Current Density ◽  
High Frequency Signal ◽  
Reflection And Transmission ◽  
Potential Barriers ◽  
Electronic Current ◽  
Electron Current Density ◽  
Device Structures ◽  
Different Types ◽  
Dc Bias ◽  
Complex Admittance

Potential barriers of different types (rectangular, triangle, parabolic) with a dc-bias and a small ac-signal in the THz-frequency band are investigated in this paper. The height of the potential barrier is modulated by the high frequency signal. If electrons penetrate through the barrier they can emit or absorb usually one or even more energy quanta, thus the electron wave function behind the barrier is a superposition of different harmonics. The time-dependent Schrödinger equation is solved to obtain the reflection and transmission amplitudes and the barrier transmittance corresponding to the harmonics. The electronic current density is calculated according to the Tsu-Esaki formula. If the harmonics of the electron current density are known, the complex admittance and other electrical parameters of the structure can be found.

MAGNETORESISTANCE IN Fe/MgO/Fe MAGNETIC TUNNEL JUNCTIONS

2007 ◽  
Vol 17 (03) ◽  
pp. 593-598 ◽  
Author(s):  
N. N. BELETSKII ◽  
S. A. BORYSENKO ◽  
V. M. YAKOVENKO ◽  
G. P. BERMAN ◽  
S. A. WOLF
Keyword(s):  
Current Density ◽  
Tunnel Junctions ◽  
Magnetic Tunnel Junctions ◽  
Tunneling Magnetoresistance ◽  
Electron Current ◽  
Ferromagnetic Electrode ◽  
Electron Current Density

The magnetoresistance of Fe/MgO/Fe magnetic tunnel junctions (MTJs) was studied taking into consideration image forces. For MTJs with an MgO insulator, explanations are given of the giant tunneling magnetoresistance (TMR) effect and the effect of the increasing TMR with an increase in MgO insulator thickness. It is demonstrated that the electron current density through MTJs can be high enough to switch the magnetization of a ferromagnetic electrode.

Effect of High Electronic Current Density on the Motion ofAu195andSb125in Gold

1966 ◽  
Vol 145 (2) ◽  
pp. 507-518 ◽  
Author(s):  
H. Michael Gilder ◽  
David Lazarus
Keyword(s):  
Current Density ◽  
Electronic Current

scholarly journals Spatial anxiety: A novel questionnaire with subscales for measuring three aspects of spatial anxiety

2018 ◽  
Vol 4 (3) ◽  
pp. 526-553 ◽  
Author(s):  
Ian M. Lyons ◽  
Gerardo Ramirez ◽  
Erin A. Maloney ◽  
Danielle N. Rendina ◽  
Susan C. Levine ◽  
...  
Keyword(s):  
External Validity ◽  
Strong Predictor ◽  
Spatial Skills ◽  
Factor Analyses ◽  
Internal Reliability ◽  
Potential Barriers ◽  
Spatial Tasks ◽  
Objective Performance ◽  
Different Types ◽  
Data Driven Approach

Spatial skills are a strong predictor of achievement and pursuit of employment in STEM fields. However, some individuals experience anxiety arising from situations that require performing spatial tasks in an evaluative context, and as a result, may avoid spatial related mental activities and exposure to spatially relevant experiences. We sought to generate and validate an instrument capable of reliably measuring individual differences in experiences of spatial anxiety. We developed a spatial anxiety data-driven approach, wherein an exploratory factor analysis was conducted within the framework for different types of spatial skills outlined by Uttal et al. (2013; https://doi.org/10.1037/a0028446). In Study 1, factor analyses revealed that items loaded on three factors that corresponded well with some of the most common spatial abilities that have been discussed in the broader literature: navigation, mental-manipulation and imagery. The three subscales were high in internal reliability and between-scale selectivity. Study 2 then established that external validity was good for the navigation and manipulation subscales: higher anxiety ratings uniquely predicted lower objective performance and lower attitude/ability ratings on established measures within the respective subdomains. External validity was acceptable for the imagery subscale, uniquely predicting lower attitude/ability ratings on an established spatial imagery questionnaire. The overall result is an empirically validated Spatial Anxiety scale for use with adults that also respects the multifaceted nature of spatial processing. This questionnaire has the potential to provide a more comprehensive screening tool for spatial anxiety, and is a step toward identifying potential barriers to STEM education.

scholarly journals Adiabatic Electronic Motion in Forming Covalent Bond

2018 ◽  
Author(s):  
Michihiro Okuyama ◽  
Fumihiko Sakata
Keyword(s):  
Current Density ◽  
Covalent Bond ◽  
Displacement Current ◽  
Dynamical Process ◽  
Electronic Density ◽  
Electronic Current ◽  
Electronic Motion ◽  
Null Value ◽  
Current Densities ◽  
The One

<div>In studying a dynamical process of the chemical reaction, it is decisive to get appropriate information from an electronic current density. To this end, we divide one-body electronic density into a couple of densities, that is, an electronic sharing density and an electronic contraction density. Since the one-body electronic current density defi ned directly through the microscopic electronic wave function gives null value under the Born-Oppenheimer molecular dynamics, we propose to employ the Maxwell's displacement current density de fined by means of the one-body electronic density obtained under the same approximation. Applying the electronic sharing and the electronic contraction current densities to a hydrogen molecule, we show these densities give important physical quantities for analyzing a dynamical process of the covalent bond.</div>

scholarly journals Characterization of thin CdTe solar cells with a CdSeTe front layer

MRS Advances ◽  
2019 ◽  
Vol 4 (37) ◽  
pp. 2053-2062
Author(s):  
Alexandra M. Bothwell ◽  
Jennifer A. Drayton ◽  
Pascal M. Jundt ◽  
James R. Sites
Keyword(s):  
Current Density ◽  
Fill Factor ◽  
Alloy Layer ◽  
Time Resolved ◽  
Loss Analysis ◽  
Cdte Solar Cells ◽  
Close Space Sublimation ◽  
Device Structures ◽  
Electroluminescence Intensity ◽  
Time Resolved Photoluminescence

ABSTRACTThin CdTe photovoltaic device efficiencies show significant improvement with the incorporation of a CdSeTe alloy layer deposited between a MgZnO emitter and CdTe absorber. CdTe and CdSeTe/CdTe devices fabricated by close-space sublimation with a total absorber thickness of 1.5 µm are studied using microscopy measurements and show minimal diffusion of Se into the CdTe. Current loss analysis shows that the CdSeTe layer is the primary absorber in the CdSeTe/CdTe structure, and fill factor loss analysis shows that ideality-factor reduction is the dominant mechanism of fill factor loss. Improvement in the CdSeTe/CdTe absorber quality compared to CdTe is also reflected in spectral and time-resolved photoluminescence measurements. Current density vs. voltage measurements show an increase in current density of up to 2 mA/cm2 with the addition of CdSeTe due to a band gap shift from 1.5 to 1.42 eV for CdTe and CdSeTe/CdTe absorbers respectively. Voltage deficit is lower with the incorporation of the CdSeTe layer, corroborated by improved electroluminescence intensity. The addition of CdSeTe into CdTe device structures has increased device efficiencies from 14.7% to 15.6% for absorbers with a total thickness less than two microns.

INFLUENCE OF SURFACTANTS ON PROPERTIES OF ELECTRORHEOLOGICAL FLUIDS CONTAINING POLYANILINE

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2461-2467 ◽  
Author(s):  
MAŁGORZATA BOCIŃSKA ◽  
HENRYK WYCIŚLIK ◽  
MARCIN OSUCHOWSKI ◽  
JANUSZ PŁOCHARSKI
Keyword(s):  
Yield Stress ◽  
Current Density ◽  
Silicone Oil ◽  
Flow Curves ◽  
Different Types ◽  
Order Of Magnitude ◽  
Dynamic Yield ◽  
Rate Of Sedimentation ◽  
Er Fluids

Sedimentation which is a natural process in most of ER fluids can be reduced by addition of surfactants that influence also other properties of the fluids. To study both the ER effect and the rate of sedimentation was the aim of the investigations. The ER fluids comprised powdered polyaniline and silicone oil to which surfactants of different polarity were added. The rate of sedimentation was measured by a sedimentation balance. The flow curves were recorded under electric field up to 2.5 kV/mm. Current density was also measured as a function of shear rate. It was found that the activity of a surfactant depends strongly on its polarity. The lipophylic surfactants stabilized the suspension very well but about 30% decrease of the dynamic yield stress was observed. The current density was reduced as well by almost one order of magnitude. The hydrophylic surfactants hardly stabilized the suspension but increase of yield stress was observed that was not followed by increase of current density. The role of different types of non-ionic surfactants was discussed.

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